15 Biggest Diet and Weight Loss Stories of 2013

By CYNTHIS SASS, MPH, RD, Health.com

Dec. 29, 2013

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One of the things I love about December is taking a look back at the previous twelve months, and what we learned as another year passed. In the nutrition world, some of the biggest revelations were clinical in nature, others fell under the realm of food psychology, and a few confirmed truths I've seen among my clients, that can now be backed by solid research. There were so many great food-related stories throughout 2013, I had a hard time narrowing my picks, but the following 15 are among those I found to be the most compelling. Here's a synopsis of each, along with my takeaway advice.

15 Biggest Diet and Weight Loss Stories of 2013

Eating fat can make you thin

A January study, published in Nutrition Journal, showed that avocado eaters have higher intakes of fiber, vitamins E and K, magnesium, and potassium, and they weigh less and have smaller waists--without eating fewer calories. Another in September from Loma Linda University concluded that without cutting calories, including avocado in meals helped reduce hunger in overweight adults and lower insulin levels.

Takeaway tip: Not all fats are created equal. While health experts have waged war on man-made trans fats, we've also tried to promote healthful varieties, and avocado is a "good fat" rock star. From whipping it into smoothies to using it in place of butter in baked goods, its uses go far beyond guacamole. For other ways to eat more, check out my previous post 6 Foods This Nutritionist Eats Every Day.

15 Biggest Diet and Weight Loss Stories of 2013

Your diet directly affects your mood

In January, a study published in the British Journal of Health Psychology found that among young adults, those who ate more fruits and veggies felt calmer, happier, and more energetic in their daily lives.

Another from Penn State in March concluded that unhealthy eating makes a bad mood worse. A third in September from University of Eastern Finland found that over a 20-year period, a healthy diet characterized by vegetables, fruits, berries, whole-grains, and lean proteins, was associated with a lower risk of depression, while a diet high in processed meats like sausages, sugary drinks, desserts, and manufactured foods, upped depression risk.

Takeaway tip: Above all, quality is king, and every food choice you make is an opportunity to influence how you feel, both physically and emotionally. In 2014, commit to eating clean, and keep that old saying "you are what you eat" top of mind, because it's literally true.

15 Biggest Diet and Weight Loss Stories of 2013

It's time to detox from sugary drinks

In a November study published in Nutrition Research, scientists analyzed data from the National Health and Nutrition Examination Survey, essentially a look into what Americans eat, to explore the link between intakes of sugary drinks and disease risk. They concluded that the decrease in the consumption of sugary beverages between 1999 and 2010 (Yeah!) was enough to slash the chances of getting heart disease by 20%. Another November story, funded by the National Cancer Institute (NCI) made headlines with the conclusion that postmenopausal women with the highest intake of sugar-sweetened beverages had a 78% increased risk for estrogen-dependent type I endometrial cancer.

Takeaway tip: Nixing sugary drinks is one of the easiest ways to slash your sugar intake. In fact, of the top 10 sources of sugar that are not put into food by Mother Nature (like the sugar in fruit), soft drinks top the list. Even three 12-ounce cans a week add up to the equivalent of over 3,000 sugar cubes a year. Reach for water instead--in addition to hydrating you, studies show it may help you naturally eat less without "dieting."

15 Biggest Diet and Weight Loss Stories of 2013

The truth about chicken nuggets revealed

In September, researchers at University of Mississippi Medical Center revealed some gruesome news about what's really in chicken nuggets. Scientists randomly selected nuggets from two different national fast food chains, then performed "autopsies" to assess the contents. They found that chicken meat was not the predominate component--it was fat, in addition to bone, nerve, and connective tissue.

Takeaway tip: No matter how busy you are, you don't have to resort to fast food. For fresh, unprocessed options that still fit into a frenzied schedule, check out my previous post 5 Healthy Alternatives to Fast Food.

15 Biggest Diet and Weight Loss Stories of 2013

You can get too much of a good thing

In October, researchers from Oregon State University revealed that excess amounts of omega-3 fatty acids may alter immune function, and disrupt the body's ability to fend off viral or bacterial infections. The scientists say the greatest risks of overdoing it come from consuming multiple sources simultaneously, like eating seafood, taking fish oil supplements, and consuming foods fortified with omega-3s, like eggs, orange juice, and cereal.

Takeaway tip: Good nutrition is all about balance, so take a Goldilocks approach--not too little, not too much, just right. For more info about nutrients you can overindulge in, and how to strike the right balance with omega-3, check out my previous post 5 Surprising Nutrients You Can Overdo.

15 Biggest Diet and Weight Loss Stories of 2013

It's more important than ever to control your blood sugar level

In February, Spanish researchers found that chronically high blood sugar levels damage cells, making them more vulnerable to cancer. And an August study from the New England Journal of Medicine found that over a 5-year period, a higher blood sugar level was tied to an increased risk of dementia, even in people without type 2 diabetes.

Takeaway tip: Curb your bad carb intake. While I don't believe that carbs are inherently evil, most Americans are consuming far too much and the wrong kinds. Take a three-pronged approach by reducing helpings of foods like pasta and rice; replacing those portions with more veggies; and upgrading to whole grain starches, like wild rice instead of white.

15 Biggest Diet and Weight Loss Stories of 2013

Make sleep a major priority

In February, a study from University of Texas Southwestern Medical Center, found that too little sleep triggered excessive eating and weight gain, and getting more sleep slashed consumption of carbs and fat, leading to weight loss. Another in June from the University of Chicago, found that getting 4.5 hours of sleep rather than 8.5 ups hunger and appetite, especially in the early afternoon.

Takeaway tip: Sleep may be more important than exercise for weight loss. Most of us fall short of the recommended eight nightly hours of slumber, and in addition to your waistline, catching too few zzzzs can also negatively impact immunity and productivity. Make it a focus in the year ahead, and check out these tips to improve your odds.l

15 Biggest Diet and Weight Loss Stories of 2013

Ditch the diet stuff

A Yale study from September found that when hungry mice were given a choice between artificial sweeteners and sugars, they were more likely to completely switch their preferences towards sugars, even if the artificial sweetener was much sweeter. The conclusion: you can't trick your brain with a fake sweetener, and trying to do so may actually drive sweet cravings. In another study from May, researchers at Washington University School of Medicine gave obese volunteers without type 2 diabetes either water or an artificial sweetener before they consumed glucose (sugar). After downing the artificial sweetener, the subjects' blood sugar peaked at a higher level than when they drank only water, and their insulin levels also rose about 20% higher.

Takeaway tip: Keep it real. If you switched from regular soda to diet beverages, ditching them in favor of good old H2O would be a great New Year's resolution. And if you're ready to say to sayonara to all artificial sweeteners, be sure to read ingredient lists--you may be surprised to find them lurking in yogurt, energy bars, cereal, and snack foods.

15 Biggest Diet and Weight Loss Stories of 2013

Curb your inner carnivore

A July study from Harvard found that over four years, increasing red meat intake by more than a half a serving a day upped type 2 diabetes risk by 48%, and reducing it by the same amount slashed the risk by 14%. In November, French researchers revealed that a higher acid load, from the consumption of animal protein, considerably upped type 2 diabetes risk. Over 14 years, compared to those with the lowest acid load, the subjects with the highest had a 58% greater risk of developing type 2 diabetes.

Takeaway tip: Even if you have no interest in becoming vegetarian or vegan, eating more plant-based meals can help you achieve a better balance. For more benefits of swapping meat for veg cuisine (including a better sex life), check out my previous post 5 Reasons to Eat More Vegetarian Meals.

15 Biggest Diet and Weight Loss Stories of 2013

Anti-inflammation can outweigh weight

In August, Irish scientists found that anti-inflammation is the key to disease protection, regardless of weight. This may explain why some overweight adults remain healthy, even though excess weight typically ups the risk of chronic diseases associated with inflammation, like heart disease and type 2 diabetes.

15 Biggest Diet and Weight Loss Stories of 2013

Eat chocolate for weight loss

In October, Spanish researchers published a study in the journal Nutrition, which found that a higher intake of chocolate was associated with lower body weight and smaller waist measurements. Another from Penn State in December concluded that in mice, cocoa reduced obesity-related inflammation, lowered insulin levels, and warded off weight gain.

15 Biggest Diet and Weight Loss Stories of 2013

Listen to your gut

In August, researchers from University of Copenhagen published a study in the journal Nature, which revealed that one in four of us have too few good intestinal bacteria. Scientists believe the deficit is tied to an increased risk of obesity, possibly due to a rise in inflammation.

Takeaway tip: Make over your gut. Consider taking a probiotic supplement, and eat more foods that contain prebiotics, which promote the growth of good bacteria in the digestive tract. They include asparagus, leeks, onions, garlic, bananas, and raisins.

15 Biggest Diet and Weight Loss Stories of 2013

Keep your salt tooth in check

In March, a report published in Nature showed that excess sodium may be tied to autoimmune diseases, such as multiple sclerosis and type 1 diabetes, by affecting the function of T cells. In a mouse model of multiple sclerosis, a high-salt diet accelerated the disease's progression.

Takeaway tip: Even if you don't have high blood pressure, cutting back on salt and sodium may help protect your health. Roughly 70% of the sodium we take in comes from processed and packaged foods, so one of the best ways to cut back is to eat more fresh fare. For example, rather than a heating up canned soup, make your own, using an organic, low-sodium vegetable broth. One cup provides just 140 mg of sodium, 9% of the daily-recommended cap, compared to over 60% in one cup of a ready-to-eat product.

15 Biggest Diet and Weight Loss Stories of 2013

Screen your sushi intake

In November, a study published in Journal of Risk Research found that mercury intakes from sushi exceed the recommended limits set by the Environmental Protection Agency. Another in June from Diabetes Care concluded that mercury exposure in young adulthood ups the risk of developing diabetes later in life.

Takeaway tip: Mercury exposure is a concern for everyone, not just pregnant women. If you're a sushi or seafood lover, check out this mercury calculator to gauge your exposure, and find out how to reduce your risk.

15 Biggest Diet and Weight Loss Stories of 2013

Go organic whenever you can

In March, researchers from Southern Methodist University found that when fruit flies (which share 75% of the genes that cause disease with humans) were fed an organic diet, they were healthier overall, lived 25% longer, and were more fertile.

Takeaway tip: Organic food is an investment in your health. Despite reports to the contrary, studies have found organic food to be nutritionally superior, including a 2009 report by the French Agency for Food Safety, which found that organically-grown foods contain more minerals, antioxidants, and beneficial fats. Organic foods also contain fewer pesticide residues, reduce exposure to antibiotic-resistant bacteria, and help support sustainable agriculture. If you're not sure which foods to prioritize, check out this handy organic guide.

Cynthia Sass is a registered dietitian with master's degrees in both nutrition science and public health. Frequently seen on national TV, she's Health's contributing nutrition editor, and privately counsels clients in New York, Los Angeles, and long distance. Cynthia is currently the sports nutrition consultant to the New York Rangers NHL team and the Tampa Bay Rays MLB team, and is board certified as a specialist in sports dietetics. Her latest New York Times best seller is S.A.S.S! Yourself Slim: Conquer Cravings, Drop Pounds and Lose Inches.